I grew up in a family where we would sometimes take a vote, and then Dad would decide. Dad had some respect for the idea of a ‘majority’ or a ‘consensus’, but I can’t remember ever worrying too much about trying to convince my siblings to vote with me.

As a scientist working for government, and later in a management position with the Queensland sugar industry, my colleagues used to try and impress upon me the importance of “having the numbers” and what the “consensus” position was.

But I’ve always been less interested in who has the numbers at any particular point in time, and more interested in the argument. I’ve always believed that a solid logical argument should eventually win the day.

“It is now firmly established, repeated ad nauseam in the media and elsewhere, that the debate over global warming has been settled by scientific consensus. The subject is closed. It seems unnecessary to labour the point, but here are a couple of typical statements: “The scientific consensus is clear: human-caused climate change is happening” (David Suzuki Foundation); “There is overwhelming scientific consensus” that greenhouse gases emitted by man cause global temperatures to rise (Mother Jones).

Back when modern science was born, the battle between consensus and new science worked the other way around. More often than not, the consensus of the time — dictated by religion, prejudice, mysticism and wild speculation, false premises — was wrong. The role of science, from Galileo to Newton and through the centuries, has been to debunk the consensus and move us forward. But now science has been stripped of its basis in experiment, knowledge, reason and the scientific method and made subject to the consensus created by politics and bureaucrats.”

The piece is interesting, it does correctly emphasis the extent to which the word ‘consensus’ is repeated invoked with the word ‘science’ and ‘climate change’ to justify support for the concept of anthropogenic global warming (AGW).

Terence Corcoran’s piece might have been improved with some reference to two well know philosophers of science, Karl Popper and Thomas Kuhn.

Popper had no time for consensus, for him science was advanced through ‘falsification’:

“Logically, no number of positive outcomes at the level of experimental testing can confirm a scientific theory, but a single genuine counter-instance is logically decisive: it shows the theory, from which the implication is derived, to be false. Popper’s account of the logical asymmetry between verification and falsification lies at the heart of his philosophy of science. It also inspired him to take falsifiability as his criterion of demarcation between what is and is not genuinely scientific: a theory should be considered scientific if and only if it is falsifiable.”

Yet so many ‘global warming believer’ complain when ‘skeptics’ present bits of information that don’t necessarily accord with the rhetoric. They might accuse the skeptic of ‘cherry picking’. But if you believe in Popper and falsification, what’s wrong with cherry picking to disprove the general applicability of a theory?

In contrast, Thomas Kuhn would perhaps see the current preoccupation with having a scientific consensus as normal:

“Thomas Kuhn … argued instead that experimental data always provide some data which cannot fit completely into a theory, and that falsification alone did not result in scientific change or an undermining of scientific consensus. He proposed that scientific consensus worked in the form of “paradigms”, which were interconnected theories and underlying assumptions about the nature of the theory itself which connected various researchers in a given field. Kuhn argued that only after the accumulation of many “significant” anomalies would scientific consensus enter a period of “crisis”. At this point, new theories would be sought out, and eventually one paradigm would triumph over the old one — a cycle of paradigm shifts rather than a linear progression towards truth. Kuhn’s model also emphasized more clearly the social and personal aspects of theory change, demonstrating through historical examples that scientific consensus was never truly a matter of pure logic or pure facts.”

So according to Kuhn the current preoccupation with a ‘scientific consensus’ on climate change is not necessarily novel and contrary to Terence Corcoran’s ascertains it doesn’t necessarily mean “the end of science”.

“Logically, no number of positive outcomes at the level of experimental testing can confirm a scientific theory, but a single genuine counter-instance is logically decisive: it shows the theory, from which the implication is derived, to be false.”

Not necessarily – Failure to explain the photoelectric effect lead to quantum theory. However classical physics is still valid and works with normal sized objects. The genuine counter-instance did not destroy classical physics only enhanced it to embrace a smaller universe that it was previously unable to explain.

As with climate science. The general framework of how we currently think the earth’s climate works is pretty well set. However the science continues to flesh out this framework with more observations. In this framework a single counter-instance cannot be a single measurement or anomoly. The atmosphere is complex enough to have single anomolies that do not prove the whole framework incorrect. The cherry-picking comes where a single measurement or anomoly is held up to be proof that the entire framework of climate science is wrong. This framework is the product of thousands of observations and bodies of work by thousands of climate scientists who largely agree that the framwork is currently the best representation of the way climate works. It is not necessarily correct or complete and no-one thinks it is.

If someone has some major evidence that global warming or any of the science is flawed – don’t complain – simply get your work published. Fame awaits those who overturn the status quo. Of course maybe your grand new idea doesn’t add up or stand the test of peer review. If so – back to the drawing board or get a job doing accounting where your creative talents will be appreciated.

How has the technological change and scientific advance that we have experienced in the last 100 years actually happened if all new ideas are stopped by this mythical consensus.

Funny that you mentioned “Mother Jones”. A close relative of mine, Rina Palta, is the assitant editor to this magazine. They deal mostly with issues regarding the Iraq war and the Iran crisis but dedicate some issues every year for environmental issues.

I think much of “cherry picking” in the climate change debate usually involves poor statistical techniques. Picking a small run of numbers or a single event. Or assuming everywhere has to respond uniformly at the same time. The study of climate involves the longer term trends in weather.

A “single genuine counter-instance is logically decisive” – this is not fully a logical proposition. The full reasons as to why a single instance may not fit a theory are sometimes unknown. The emphasis is on how to define “genuine”.

Many departing examples would start to generate a concern. However, students of statistics are told to value their outliers.

In the past there have been fierce scientific controversies in many fields. Bill Bryson’s “A Short History of Almost Everything” is a fascinating read that recounts some of these controversies. Often, the older generation of scientists had to pass away before newer ideas gained acceptance.

I wonder if the “concensus” on global warming is more a concensus built around the concept that industrial activity is wrecking the planet, and global warming is just the current manifestation of this idea.

After all, Stephen Schneider once thought that the earth could enter a new ice age due to temperature decline caused by industrial pollution of the atmosphere by aerosols (and that increased CO2 would not cause a significant temperature rise). Now he thinks that increased CO2 from industrial action will cause a significant temperature rise. The paradigm in both cases is that human activity is deleterious to the environment.

Bjorn Borg demonstrated that human industrial action is not always bad for the environment. By challenging the dominant paradigm, he was savagely attacked. Incidentally, a similar thing happened when Uffe Ravnskov challenged the diet/cholesterol/heart attack concensus.

If the earth is in fact entering a cooling phase due to decreased sunspot activity, I expect the industrial aerosol cooling theory will be given a rerun.

Sigh .. no it’s built around what carbon dioxide does with infra-red radiation, and the associated models of radiative physics. The history of the topic doesn’t show that at all. And an excellent example of cherry picking to boot.

There’s another side of who’s the attacker and who’s the attackee in this debate. Is the underdog those who disagree with global warming science or those that assert that global warming science is indeed correct. Only until the recent decade has the mainstream of society come to seriously consider it more than a possibility. How many people at large would consider global warming a major issue in 1980 or 1990 ?

If observational data, not computer models, shows that in the period 1950 to 2005 carbon dioxide increases as a consequence of an increase in temperature and that there is no observable increase in temperature following an increase in CO2, then is the observational data demostrating the true situation or should everyone belive the so-called consensus?

Here we go. It’s got nothing to do with consensus. It’s got to do with well established physics, validated by models. I hope you’re not one of those linearists are you. This is why we have “models” which integrate more than one influence at a time, such is also occurring today in Australia. In any case there is also plenty of empirical evidence of the effect. If you’re going to argue that, I don’t think it’s worth continuing as nothing will convince you.

Gerry, you illustrate your atitude perfectly by your reaction to my hypothetical. You show distain for observational data by your belief in computer models.

Models are based on assumptions which are the product of hypotheses. If invalid assumptions are made then the model is useless. Hypotheses come with uncertainties but computer models are very poor at representing these. If each assumption has 90% certainty then it only takes 7 such assumptions of equal weight before confidence in the result falls below 50%.

You also delude yourself if you think that climate models are accurate. I’ve published (in a peer-reviewed journal) my findings that the CSIRO’s climate reports, each based on a number of such models, simply lack credibility. The CSIRO reports are not exactly presented in a way that lets you properly appreciate how inaccurate their “hindcasts” of 1950-2000 really are!

I have also found a very clear relationship between a certain climate factor and average global temperature. The relationship not only produces very accurate estimates of temperature but (a) the lack of papers on the subject suggest that it’s poorly understood and most likely missing from climate models and (b) it shows that recent warming is not anthropogenic at all.

This discussion is about consensus v. evidence that contradicts that position. I’ll ask you again, IF clear evidence refutes that consensus then what should we believe?

I’m certainly not going to believe some anonymous punter like yourself on a random blog so you answer the question.

Of course anyone with a good argument and evidence should be listened too. But it’s not just your word or the fact you’re published – there can be a debate and a rebuttal. That’s why there are so many return fire follow-ups in various journals where others contest publications and their findings. Science can be a feisty business.

It just doesn’t all stop with one publication does it. You’ve just asserted that you have overturned a massive body of science. If you have – well – very well done. Hat tilt, applause and bows. If not – well it be consigned to the scrap bin of history.

But your bluster and failure to answer my basic questions fuels my suspicions it’s a backwater non-mainstream climate journal, lightly refereed or nil, and you haven’t spoken to the staff in CSIRO who do this type of research.

John – “If observational data, not computer models, shows that in the period 1950 to 2005 carbon dioxide increases as a consequence of an increase in temperature and that there is no observable increase in temperature following an increase in CO2, then is the observational data demostrating the true situation or should everyone belive the so-called consensus?”

What observational data show this? What mechanism makes CO2 rise as a function of temperature? Where does the gigatons of CO2 that are released from fossil fuels go?

You are simply a bigot when it comes to the question of climate change. The consensus is all that matters to you and your mind is entirely closed to alternatives.

If you were not bigotted you would be requesting to see
(a) the peer-reviewed paper that says the CSIRO reports lack credibility
and (b) evidence of my assertion that ignored natural forces are determining global temperature

Sadly your attitude is common rather than rare.

Ender, who I usually argue with, has at least asked questions and shown a willingness to investigate.

I want to ignore his first question for the moment (and maybe answer it in a couple of months – sorry) and concentrate on his 2nd and 3rd. As temperature increases (a) most vegetation absorbs less CO2 and (b) the sea-surface temperature rises and reduces the net absorption into the oceans. Continued higher temperatures will naturally mean that less CO2 is absorbed and the annual increase in atmospheric CO2 is actually increasing. On his last question, the gigatons of CO2 from fossil fuel might sound like an impressive amount but it is very small compared to the natural emissions. Not surprisingly the isotope of CO2 from vegetation is identical to the isotope of CO2 from fossil fuel and it is not possible to clearly determine which of these sources contributed to the atmospheric CO2. (BTW, atmospheric CO2 is a different isotope, probably due to exposure to radiation over an extended period, much like many plastics going brittle in sunlight.)

“A brief aside on carbon isotopes — carbon atoms don’t always have the same number of neutrons in them, so they occur with different atomic weights 14, 13, and 12, with 12C making up around 98.9%, 13C making up about 1.1%, radioactive 14C, the radioactive one making up a tiny fraction. 12C and 13C are stable isotopes meaning they do not decay, while 14C has a half-life of 5270 years and is continually being produced when 14N in the atmosphere interacts with high-energy solar radiation.) The CO2 produced by burning fossil fuels has a much lower ratio of 13C /12C than normal atmospheric CO2. If we were adding new CO2 that had the same ratio as the rest of the carbon in the atmosphere, the total amount of carbon will increase, but the 13C /12C ratio will stay the same; so by adding new with a much lower ratio of 13C /12C, we are diluting the atmospheric ratio of 13C /12C.”

The carbon ratio is pretty well understood and forms the basis of C14 dating which is pretty accurate. When a carbon based thing is fossilised for whatever reason it stops taking in C14. This C14 then decays changing the ratio of C12/C13 so the signature of fossil C is pretty clear.

As well:
“A final test comes from the fact that the carbon released from burning fossil fuels is essentially devoid of 14C, which has a short (5270 years) half-life; much of the fossil fuel we burn is on the order of 50 to 100 million years old, hence its depletion in 14C. So, if our hypothesis is correct, then there should be a measurable decline in the concentration of 14C in the atmosphere, beginning at about the time when we started to burn fossil fuels to fuel our industrial revolution. Indeed, this decline in atmospheric 14C is observed, further strengthening our hypothesis that the rise in atmospheric CO2 is caused by our burning of fossil fuels.”

As I understand the situation Popper was concerned with the problem of Induction. This is the same problem that engaged the attention of the eighteenth century philosopher David Hume. Let me explain, it has been observed that the sun rises daily. Hypothesis the rising of the sun will continue to be a daily occurrence into the future. On January 1st 2050 the sun is not seen to rise, therefore the hypothesis is falsified. More observations are made on 2nd, 3rd January it is confirmed the sun no longer rises at the brake of day. Is not the falsification by negation also an inductive process?

Another example an astronomical experiment was performed in 1919 by Arthur Eddington to determine the question of Newtonian mechanics v relativity mechanics. As is well known Einstein’s theory won the day. But was not the apparatus used by Eddington designed according to Newtonian principles and Euclidean geometry.

Jennifer backs a “solid logical argument”
Humans have a deeply ingrained ability to deceive themselves, particularly fixed personality types (they unconsciously scan for data to support their early judgements and preconceptions).

You may think you’ve chosen the most logical outcome but you may be deceiving yourself. How do you test for that, especially when the issue runs much deeper than straightforward basic science? Many times I’ve seen decision makers convinced by the tactics and persuasiveness of the arguer over valid truth behind the argument.

“..For Popper, a hypothesis is scientific only if it has the potential to be refuted by some possible observation. There are serious problems with this formula, and hardly any philosophers would accept anything as simple as this. It is a fantasy to think that big theoretical ideas in science are set up in such a way that they can be knocked out, with logical certainty, if some single crucial observation is found. For example, all scientific ideas, especially the big theoretical ones, only make predictions about observations when assumptions are made about many other matters (for example, the experimental apparatus and the circumstances of observation). But no one has come up with a reasonably simple alternative formula to Popper’s one that does much better. So is it hopeless to try to say something simple and general about how science differs from other kinds of inquiry?..”

Ender, I might point out that the loss of C14 by radioactive decay will do almost nothing to change the C12-C13 ratio as the amount of C14 is very very very small (of order of kilograms in the entire atmosphere, I believe). What is hapening is that fossil fuels are very old and have no C14. In the atmosphere before the atom bomb testing, the dilution of C14 of cosmogenic origin in the atmospheric CO2 was measurable, now it is hidden under the “bomb pulse”. The effect is known as Suess effect, after its discover.

The C12/C13 ratio of CO2 from fossil fuels is significantly different from CO2 from the biosphere and the atmosphere is very clearly changing due to fossil fuels. The record from Cape Grim clearly shows the recent record and Ice core data from Antartica clearly shows a stable patern before human intervention.

To really show that climate change is false we need to perform observations at a planetry level and show that other planets like earth do not under go climate change as a result of greenhouse gas increases. A few internal observations contridicting the current hypothesis are not enough to falsify the hyothesis in the light of all the other evidence (its a matter of scale)

Malcolm – “Who gives a toss if John, Jim, Ender, Rog or who ever is right or wrong, humanity is still better off spending its money and resources fixing up the real problems that we do know something about.”

Fair enough on the list of priorities perhaps. I don’t think any believer in climate change would argue that the list of other issues is compelling.

But let’s not totally throw everything out. If climate change leads to signficant food or health impacts down the track – you’ll be stuck with it. No point in crying about it then. Climate is already a massive influence on people’s lives.

The operative and highly biased phrase is “real problems that we do know something about”. I think we might know a bit.

But let’s get really serious – let’s ban all unnecessary waste everywhere – cancel vast wastes of money and resources like the Olympics, international sporting events like the World Cup soccer, Grand Prix car racing, the Americas cup, pleasure cruises, overseas holidays, making zillion dollar movies, etc. Let’s not dilly dally or undulge ourselves – let’s spend all that money on fixing Africa and the third world.

Gerry – I am still waiting for the answer to the question that I have put to you several times.

Here it is again – If clear evidence refutes the common consensus about anthropogenic warming then what should we believe – the consensus or the evidence ?

Ender – Something of timely interest from another Internet discussion “…You will find various estimates and I stress they are all estimates but it is generally conceded that humans add 6 GT (gigatons) to the atmosphere. However, it is also estimated we remove 3 GT mostly through agriculture, but also forestry. The next challenge is to find out how much CO2 there is in the atmosphere and again there is a variance of estimates from 750 GT to 820 GT.”

Meanwhile back at the discussion about consensus v. contradictory evidence … I’d like to remind everyone that there’s a number of scientific consensuses (consensi ?) that have been overturned – the arrangement of the solar system, the causes of diseases, continental drift and the notion of Ice Ages spring immediately to mind. I wonder what it took to overturn the respective consensuses – was it consistent and ongoing evidence?. Also, what was the pattern of acceptance – was belief changed in a relatively short time or did people cling to out-dated beliefs until their position became untenable?

We can add another overturned consensus to your list: the global climate is not being effected by human activities. A widely held belief in the scientific community only a decade or two ago.

That case study will reveal people cling to ideas long after reason and evidence should have had them let go and move on.

Re: removing 3Gt of (C or CO2?) you should provide a source. I suspect if you did we would see that it is a regional flux or it is not a net figure. The IPCC TAR indicates a global net flux of .2 Gt C into land due to human activitieshttp://www.grida.no/climate/ipcc_tar/wg1/fig3-1.htm

“If clear evidence refutes the common consensus about anthropogenic warming then what should we believe – the consensus or the evidence?”

John – “Something of timely interest from another Internet discussion “…You will find various estimates and I stress they are all estimates but it is generally conceded that humans add 6 GT (gigatons) to the atmosphere.”

However it is not the absolute amount that matters only the imbalance. Consider a sensitive balance beam with 1000kg on one side and 1000.001kg on the other. If the balance is sufficiently sensitive it will tip to the side that is 1000.001kg even though the difference is only 1 gram. To say that anthropogenic emmissions is only a small amount compared to natural emissions is the same as saying that 1 gram on the end of beam that goes down does not matter because it is only 1 gram. Yet the beam still goes down at the heavier end.

In the same way the atmosphere is extremely sensitive to the amount of greenhouse gases contained within it. Because these gases regulate the amount of heat leaving the Earth’s and this is an enormous amount of energy that they control, very small changes in concentration of greenhouse gases can change the heat balance even though the amount is small in relation to the amounts of carbon moving in and out of the biosphere.

“Also, what was the pattern of acceptance – was belief changed in a relatively short time or did people cling to out-dated beliefs until their position became untenable?”

Lomborgs and Bolton’s UN Group prioritised the issues of the world and humanity and put AGW stone motherly last. They did so because the issues are well understood, and are happening now, in front of everyones eyes, and can/should be fixed. You know, simple things like millions dieing of hunger.
Contrast that with the potential impact of AGW which may manifest itself in years to come, and which may or may not cause death and destruction, that could not have been avoided by adaptation.

Obviously it hasnt take much nouse to objectively work out where one should spend the time and energy. But if one is a myopic scientist who is only concerned with his/her immediate place in the sun,( and the next funding grant) then sure, AGW must be the most important thing imaginable, and completely overide everything else.

As someone else said,handing over the keys of the treasury to a bunch of AGW academics and bueureaucrats would be sure fire way of sending us all broke and making sure that there would be no chance at all of solving any of the other problems,and AGW,over the next 50 years or so.

John – as I said before – we go with the clear evidence. That’s what is being done. Now you answer my questions about your backwater paper that we don’t know about.

Malcolm – who says it’s the most important issue – that’s just your assertion. As for sending us all broke – twaddle. Just more of Lomborg’s discredited myopic b/s. It could actually be an economic opportunity if we approach it sensibly.

John, please look at the Cape Grim isotope time series before you say that the CO2 from the current biosphere is the same as from fossil carbon, for a start C4 grasslands did not exist when most fossil carbon was being deposited and these grasses have a very different C12/C13 ratio to coal. Oceans also modify the isotope ratio so CO2 from here is also not like that from coal. SEE http://aadc-maps.aad.gov.au/aadc/soe/display_indicator.cfm?soe_id=11

Malcolm Hill – “Contrast that with the potential impact of AGW which may manifest itself in years to come, and which may or may not cause death and destruction, that could not have been avoided by adaptation.”

How do you know this is true? How do you know that climate change will not be too rapid for easy adaption?

“You know, simple things like millions dieing of hunger. ”

Why do assume or use this argument that all the money is going to help the climate which will leave nothing for helping the other problems. The world is rich enough to do both. Also the measures to reduce greenhouse gases may not be that expensive. What is your answer to the coming shortage of liquid fuels? There is no point giving hungy people food if they cannot afford the fuel to cook it with.

All States have competing demands for funds available, and generally they look at maximising the social and economic returns on these funds.

Thats what was interesting about the Lomborg and Bolton exercises in that they were prioritising the competing interests on a trans national scale.

AGW and its currently fashionable solution, namely Kyoto would cost a a bomb and achieve bugger all in terms reducing the source of the percieved threat. Like I said, its pretty straight forward stuff.

Until the AGW proponents can come up with a better and more honest account of their case, together with a more plausible/practible solution set, then it will always be ranked low, and governments will continue to pay it lip service.

Malcolm – “Thats what was interesting about the Lomborg and Bolton exercises in that they were prioritising the competing interests on a trans national scale.”

Again how do you know Lomborg and Bolton are correct in their priorities?

“Until the AGW proponents can come up with a better and more honest account of their case”

Are you suggesting the the climate scientists are dishonest? What you are really saying is that they have to come up with something that fits your preconceived notions and/or allow people to go on making obscene amounts of money for you to approve of it.

So far you have avoided answering any of the questions I have posed – perhaps you now could start.

No I havnt avoided any proper questions.Your questions are trite nonsense that say more about you.

For example.The Lomborg and Bolton priorities were those of groups, with some knowledge world issues and finances/economics, and used a structured process to arrive at their conclusions. The point being made was that they all ranked other issues a higher than AGW.

Malcolm – “No I havnt avoided any proper questions.Your questions are trite nonsense that say more about you.”

So your references are true because they are true?

So here is the trite nonsense that you do not seem to be able to answer:
How do you know this is true? How do you know that climate change will not be too rapid for easy adaption?
What is your answer to the coming shortage of liquid fuels? There is no point giving hungy people food if they cannot afford the fuel to cook it with.
Are you suggesting that the climate scientists are dishonest?

Perhaps you can also supply other studies confirming the Lomborg and Bolton studies after you have a go at these questions. Or are we to assume that your word along with Lomborg and Bolton are self evident.

The Lomborg and Bolton groups have done a job of work to put some priority on known issues currently affecting humanity. Sensible pragmatic people and organisations do this all the time when they are dealing with other peoples lives and money. In undertaking this exercise one would normally assume they are across all the relevent data pertaining to that issue.Pragmatic people also make decisions (when they have to make that decision) based upon what they know, or not know, at that time. If there is clearly insufficient data to make a call one way or another, then it may be set aside. That is life.

How do I know if AGW may or may not move too quickly for progressive adaptation?. I dont. Do you?.But what I do know is that in the absence of any reliable data, it is a folly to invest the bank on a low probability outcome,when there are more pressing matters.

What is my answer to a prospective shortage of liquid fuels. Trust in the market and rational government. Whats yours?. Spend the bank again.

Am I suggesting that scientists are dishonest?. Some clearly are, and that is well documented. Sadly fraud is as common place with the scientific fraternity, as any other domain.

So is gilding the lily by scientists on behalf of vested interests, and their own.

I assume that is why Govts are so careful about not jumping too quickly onto scientific driven band wagons, like AGW.

So when decision makers and advisers like the Lomborg and Bolton groups get together to determine some priority for these investments/policies, for the good of everyone, it is as good a sounding board as any.

That they chose to put AGW way down the list, and last in one of them, is a measure of what world Govts really think.

Malcolm – Combining you 2 quotes “Lomborg and Bolton groups ” and “Am I suggesting that scientists are dishonest?. Some clearly are, and that is well documented.”
would suggest that Lomborg and Bolton could be dishonest as well. So who do you trust – the ones that speak what you want to hear?

Putting AGW down the list is OK while the climate is sort of alright however why do we have to wait until is goes pear shaped to do anything. You have admitted that you do not know whether the climate change will be rapid or not. I do not know either – nobody does. However you are making the potentially dangerous assumption, without any evidence, that it will be benign and slow.

World govenments only look at the share market until something else comes up that they have to look at.

Liquid fuels – I guess you can ignore this one as well as I guess the twin gods of market forces and technology will magically create more light sweet crude nice and cheap.

The issue is whether AGW is of sufficient significance to warrant countermeasures.

After reviewing the Blog and comments together with what I have learned from observations based upon historical data, in my view, the preponderance of the evidence weighs in favor of AGW being of very minor importance. While reliability of extensive historical data is often subject to question the parameters of error overall cannot compare to error in unproven computer projection modeling in any compelling or credible way. Chaos dynamics are not reliably applicable to proof re AGW since accurate data is too small. Linear historical models are a much more practical and credible predictor of climate future and should override speculative computer modeling. We should pay more attention to documentable historical data which support laws of nature than theoretical analysis. Atmospheric CO2 is the same CO2 that existed for the past reliably recorded 600,000 years of atmospheric history and, unless you dispense with all common sense, must have been. at various periods of global warming, existing in vastly greater amounts than can predictably occur over the next century including all human generated CO2. This occurred without linked devastation of any kind. So why are we terrorized by the brief resurgence of a relatively small amount of CO2 as a result of human activity. Some thoughts:

1. CO2 data, regardless of precise reliability, relating to climate change over the past 600,000 years with seven major interglacial periods, consistently indicates CO2 increase connected to GW is preceded at considerable length by increased solar radiation not the other way around. There is no provable correlation of significant increased radiation due to increase of CO2 during those periods. Our current and possibly anomalous global warming cycle commenced 180 years ago with human induced CO2 increase of significance only during the last 60 years. What is interesting is that the warming trend has not deviated upward in correlation to the CO2 increase. Does this, in its limited time span, prove anything either way? Maybe not – but why speculate with such non-existent or weak evidence.

2.If we average temperatures over the past 3,000 years we are right on the average mark, a very comfortable place to be. We should welcome the return of CO2 with its benefit to plant and animal growth, especially in biologically stressed areas of the world, not be frightened by it.

3. If we accept 6 gigatons as the amount of Human produced CO2 and 800 gigagtons of CO2 moving in and out of the oceans, land and atmosphere it takes a huge stretch of the imagination to believe that climate over a short period of time, i.e. less than a century, would be affected by AGW more than a small percentage of one centigrade of temperature change. The argument that global atmosphere temperature is “extremely” sensitive to increase in CO2 begs the entire question of the effect of AGW, is not proven historically but only evinced by some modeling most of which is for good reason controversial hence speculative.

4. The claim that there is “scientific” consensus on AGW is interesting because of the arrogance of those that make it. There is certainly no scientific consensus only political consensus amongst liberals such as Al Gore whose highest grade in any science course was a C. At one point there was a consensus that the world was flat and that the sun revolved around the earth. So the word “consensus” should rarely be used in the scientific community and never with position controversies such as anthropogenic global warming. This greatly misleads the uneducated masses when the appropriate words are: “many” or even “most” scientific experts on the subject tend to “believe” AGW has a serious impact on life which needs to be addressed.
I don’t know if the truly knowledgeable experts on global warming and CO2 have ever been identified much less polled. But, to the extent such experts believe CO2, in uncontroveted AGW amounts, signifcantly warms the atmosphere, in total denial of historical observational evidence, I want a lot more than statistical data set and computer generated hypothesis modeled speculation. I want solid proof in degrees of heat documenting the effect of solar radiation on diffused CO2 with elaborate experimental validation. Otherwise, even with “experts” it is all smoke and mirrors.